Celestial fireworks to mark 25 years of the Hubble telescope

Important discoveries flowed from telescope that orbits earth at a distance of 550km

The Hubble telescope marks its 25th year in service on Friday, with celebrations focusing on the remarkable images it has captured since coming into operation in 1990.

What must rank as the world’s most famous telescope in the world is also out of this world, literally. It orbits the earth 550km up, taking amazing pictures free from the distortion caused by the earth’s atmosphere.

A joint effort by the US and European space agencies, it has transformed our view of the universe.

It has captured near incomprehensible volumes of data using its 2.4 metre mirror and recording what it sees in ultraviolet, visible and infrared light.

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“It has made an absolutely amazing contribution,” says Prof Tom Ray, professor of astronomy at the Dublin Institute for Advanced Studies and a specialist in star formation.

"I have used it quite a number of times as have others in Ireland through our membership of the European Space Agency, " he says. "It is a phenomenal telescope."

It helped astronomers establish the age of the universe at 13.5 billion years. It also helped establish a measure for distances across the universe and also proof of the laws of physics.

All this nearly didn’t come to pass. Within weeks of launching mission controllers discovered the tiniest of errors in the mirror’s surface measuring no more than two millionths of a meter. Yet this was enough to cause distortion of the distant images being studied.

It was always intended Hubble would have regular services and updates via the space shuttle. Software and hardware “spectacles” were made and astronauts uploaded these bringing the telescope back into working order.

Hubble has provided the best visible light images ever captured by a telescope and there has been a constant stream of striking images from it.

The one released to mark its silver anniversary is of a cluster of 3,000 stars called Westerlund 2. It was chosen because it so resembles a fireworks display but in fact it is a place of rapid star formation.

To see more images visit this site: http://hubblesite.org/gallery/

Dick Ahlstrom

Dick Ahlstrom

Dick Ahlstrom, a contributor to The Irish Times, is the newspaper's former Science Editor.